From: Kirill Tkhai <ktkhai@virtuozzo.com>
To: akpm@linux-foundation.org, gregkh@linuxfoundation.org,
rafael@kernel.org, viro@zeniv.linux.org.uk,
darrick.wong@oracle.com, paulmck@linux.vnet.ibm.com,
josh@joshtriplett.org, rostedt@goodmis.org,
mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com,
hughd@google.com, shuah@kernel.org, robh@kernel.org,
ulf.hansson@linaro.org, aspriel@gmail.com,
vivek.gautam@codeaurora.org, robin.murphy@arm.com,
joe@perches.com, heikki.krogerus@linux.intel.com,
ktkhai@virtuozzo.com, sfr@canb.auug.org.au,
vdavydov.dev@gmail.com, mhocko@suse.com,
chris@chris-wilson.co.uk, penguin-kernel@I-love.SAKURA.ne.jp,
aryabinin@virtuozzo.com, willy@infradead.org,
ying.huang@intel.com, shakeelb@google.com, jbacik@fb.com,
mingo@kernel.org, mhiramat@kernel.org,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-mm@kvack.org
Subject: [PATCH RFC 06/10] fs: Shrink only (SB_ACTIVE|SB_BORN) superblocks in super_cache_scan()
Date: Tue, 07 Aug 2018 18:38:36 +0300 [thread overview]
Message-ID: <153365631661.19074.12075476211623702890.stgit@localhost.localdomain> (raw)
In-Reply-To: <153365347929.19074.12509495712735843805.stgit@localhost.localdomain>
This patch prepares superblock shrinker for delayed unregistering.
It makes super_cache_scan() avoid shrinking of not active superblocks.
SB_ACTIVE is used as such the indicator. In case of superblock is not
active, super_cache_scan() just exits with SHRINK_STOP as result.
Note, that SB_ACTIVE is cleared in generic_shutdown_super() and this
is made under s_umount mutex. Function super_cache_scan() also takes
the mutex, so it can't skip this flag cleared.
SB_BORN check is added to super_cache_scan() just for uniformity
with super_cache_count(), while super_cache_count() received SB_ACTIVE
check just for uniformity with super_cache_scan().
After this patch super_cache_scan() becomes to ignore unregistering
superblocks, so this function is OK with splitting unregister_shrinker().
Next patches prepare super_cache_count() to follow this way.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
---
fs/super.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/fs/super.c b/fs/super.c
index 457834278e37..9222cfc196bf 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -79,6 +79,11 @@ static unsigned long super_cache_scan(struct shrinker *shrink,
if (!trylock_super(sb))
return SHRINK_STOP;
+ if ((sb->s_flags & (SB_BORN|SB_ACTIVE)) != (SB_BORN|SB_ACTIVE)) {
+ freed = SHRINK_STOP;
+ goto unlock;
+ }
+
if (sb->s_op->nr_cached_objects)
fs_objects = sb->s_op->nr_cached_objects(sb, sc);
@@ -110,6 +115,7 @@ static unsigned long super_cache_scan(struct shrinker *shrink,
freed += sb->s_op->free_cached_objects(sb, sc);
}
+unlock:
up_read(&sb->s_umount);
return freed;
}
@@ -136,7 +142,7 @@ static unsigned long super_cache_count(struct shrinker *shrink,
* avoid this situation, so do the same here. The memory barrier is
* matched with the one in mount_fs() as we don't hold locks here.
*/
- if (!(sb->s_flags & SB_BORN))
+ if ((sb->s_flags & (SB_BORN|SB_ACTIVE)) != (SB_BORN|SB_ACTIVE))
return 0;
smp_rmb();
next prev parent reply other threads:[~2018-08-07 15:38 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-07 15:37 [PATCH RFC 00/10] Introduce lockless shrink_slab() Kirill Tkhai
2018-08-07 15:37 ` [PATCH RFC 01/10] rcu: Make CONFIG_SRCU unconditionally enabled Kirill Tkhai
2018-08-08 0:55 ` Steven Rostedt
2018-08-08 1:05 ` Stephen Rothwell
2018-08-08 9:46 ` Kirill Tkhai
2018-08-08 1:08 ` Stephen Rothwell
2018-08-08 9:59 ` Kirill Tkhai
2018-08-08 11:04 ` Stephen Rothwell
2018-08-08 7:20 ` Michal Hocko
2018-08-08 10:17 ` Kirill Tkhai
2018-08-08 10:27 ` Michal Hocko
2018-08-08 21:31 ` Dave Chinner
2018-08-09 0:07 ` Matthew Wilcox
2018-08-09 7:45 ` Greg KH
2018-08-09 10:22 ` Kirill Tkhai
2018-08-08 16:13 ` Josh Triplett
2018-08-08 16:23 ` Kirill Tkhai
2018-08-08 16:30 ` Kirill Tkhai
2018-08-08 18:01 ` Josh Triplett
2018-08-08 23:02 ` Shakeel Butt
2018-08-08 23:09 ` Josh Triplett
2018-08-07 15:37 ` [PATCH RFC 02/10] mm: Make shrink_slab() lockless Kirill Tkhai
2018-08-08 11:51 ` Kirill Tkhai
2018-08-08 12:36 ` Tetsuo Handa
2018-08-08 12:51 ` Kirill Tkhai
2018-08-08 13:20 ` [PATCH RFC v2 " Kirill Tkhai
2018-08-09 7:14 ` Michal Hocko
2018-08-09 9:21 ` Kirill Tkhai
2018-08-09 10:37 ` Tetsuo Handa
2018-08-09 10:58 ` Kirill Tkhai
2018-08-09 11:23 ` Kirill Tkhai
2018-08-07 15:38 ` [PATCH RFC 03/10] mm: Convert shrinker_rwsem to mutex Kirill Tkhai
2018-08-07 15:38 ` [PATCH RFC 04/10] mm: Split unregister_shrinker() Kirill Tkhai
2018-08-07 15:38 ` [PATCH RFC 05/10] fs: Move list_lru_destroy() to destroy_super_work() Kirill Tkhai
2018-08-07 15:38 ` Kirill Tkhai [this message]
2018-08-07 15:38 ` [PATCH RFC 07/10] fs: Introduce struct super_operations::destroy_super() callback Kirill Tkhai
2018-08-07 15:39 ` [PATCH RFC 08/10] xfs: Introduce xfs_fs_destroy_super() Kirill Tkhai
2018-08-07 15:39 ` [PATCH RFC 09/10] shmem: Implement shmem_destroy_super() Kirill Tkhai
2018-08-07 15:39 ` [PATCH RFC 10/10] fs: Use unregister_shrinker_delayed_{initiate, finalize} for super_block shrinker Kirill Tkhai
2018-08-08 1:12 ` [PATCH RFC 00/10] Introduce lockless shrink_slab() Stephen Rothwell
2018-08-08 5:39 ` Shakeel Butt
2018-08-08 10:18 ` Kirill Tkhai
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